Sucker rods

Abstract

The sucker rod system in a deep well sucker rod pump consists of a plurality of unidirectionally reinforced composite fiber rods extending substantially parallel but not in contact with each other, the cross-sectional area of which rods is less than 1 cm 2 . This enables the advantageous material properties to be utilized to a high degree. The sucker rod system can be assembled on site. The individual composite fiber rods can be monitored when they are in the working position.

What is claimed is: 
     
       1. In a deep well sucker rod pump wherein a piston suspended from a system of sucker rods in a rising pipe is moved up and down in a pump casing at the bottom of the rising pipe by an above ground pump drive, the improvement wherein the sucker rod system comprises a plurality of unidirectionally reinforced composite fiber rods each having a cross-sectional area of from 20 to 100 mm 2  and spacer means connected to the rods to maintain the rods substantially parallel to each other and not in contact with each other. 
     
     
       2. The system according to claim 1, further comprising an upper and lower anchoring clamping plate connecting the sucker rods with the piston and its drive. 
     
     
       3. The system according to claim 2, further comprising an electric conductor in each composite fiber rod, means joining the conductors together in the region of the lower anchoring clamping plate and a conductivity measuring instrument connected to the conductors. 
     
     
       4. The system according to claim 2, wherein each composite fiber rod contains a metallic conductor and the conductors extend sufficiently far out in the region of the upper anchoring clamping plate and connectable to an instrument for measuring ultrasound. 
     
     
       5. The system according to claim 2, wherein each composite fiber rod contains a photoconductive cable and the photoconductive cables extend sufficiently far out in the region of the upper clamping plate to be connectable to an instrument for measuring the attenuation of light. 
     
     
       6. The system according to claim 1, wherein the spacing means comprise spacers of plastic material clamped to the composite fiber rods and configured to guide the sucker rod system in the rising pipe. 
     
     
       7. The system according to claim 1, further comprising a plastic cylinder clamped to the composite fiber rods to seal off the sucker rod system at the upper end of the rising pipe. 
     
     
       8. The system according to claim 1, wherein the sucker rod system consists of differing composite fiber rods, including those with differing fibers or proportions of fibers. 
     
     
       9. The system according to claim 1, wherein the composite fiber rods are sheathed in thermoplastic polymers.